Centrifugal separator



Apnl 15, 1969 J. MURKES ET CENTRIFUGAL SEPARATOR I of 5 Sheet Filed Feb.25. 1966 Q it 2 70 k0 b lfurkgs Car! Gd'ron M'Zsan jaw;

April 15, 1969 J MURKES ET AL 3,438,571

CENTRIFUGAL SEPARATOR Filed Feb. 25, 1966 Sheet 2 of 5 In van or JakobHurkeS April 15, 1969 MURKES ET AL CENTRIFUGAL SEPARATOR Sheet FiledFeb. 25, 1966 Inventor Jakob Nurkes Carl G'ron M'lson April 15, 1969MURKES ET AL CENTRIFUGAL SEPARATOR Sheet 5' ors Filed Feb. 25, 1966 Inven to Jakob Nurkes COrl- 60"!0/1 Mlsan United States Patent U.S. Cl.233-2 Claims ABSTRACT OF THE DISCLOSURE A centrifugal rotor is providedwith an inlet for a mixture of two liquids to be separated and has aseparating chamber including an outer peripheral portion and a mainseparating space, the rotor defining a completely open feed passage fromthe inlet to the peripheral portion of the separating chamber. The rotoralso defines first and second flow paths leading from the outer portionof the open feed passage or from the peripheral portion of theseparating chamber to respective outlets for the two separated liquids,these outlets being spaced radially inward from the aforesaid peripheralportion, the first flow path including the main space of the separatingchamber. A porous body is inserted in one of these flow paths,preferably the first, and is of either the type operable to coalescedroplets of one of the liquids passing therethrough or the type operableto block the passage of one of the liquids. The open feed passage fromthe inlet allows any solids in the feed mixture to pass directly to theperipheral portion of the separating chamber and thus avoid clogging ofthe porous body.

The present invention relates to a centrifugal separator for theseparation of two liquids from each other.

In the separation of a liquid mixture, such as Water droplets in oil oroil droplets in water, it is often desirable that one of the separatedliquids (for example, the oil) is freed a high degree from contaminationby the other liquid. If the droplets are of a very small size, it isdifficult to reach the desired separation efficiency, even in acentrifugal separator.

According to the present invention, it is possible to obtain aconsiderably improved separation result if a porous body is inserted inthe flow path to or through the separator, said porous body being ofsuch a kind known per se that, upon passage of a liquid mixture throughthe body, droplets of one of the liquids will coalesce, or of such akind known per se that only the continuous liquid phase passes throughthe body. The latter case implies that the liquid droplets are separatedfrom the continuous liquid phase. In order to obtain a satisfactoryseparation result, it is advantageous if the droplets can be caused tocoalesce prior to their admittance to the separator or after they havebeen entrained in the rotation of the separator because, as known, largedroplets are separated more rapidly from a liquid than small droplets.Accordingly, a coalescing, porous body may be inserted in the stationaryinlet of the separator.

Since the entrainment in the rotation of the separator of the liquid fedinto the separator causes a certain fragmentation of the droplets, itmay be desirable to insert said body in the distributor, moreparticularly at a certain distance inside said distributor, where arotational speed has already been imparted to the liquid. It is thuspreferable to use a substantially tubular or ringshaped, coalescing,porous body, which is coaxial with the axis of rotation of the separatorand surrounds the periphery of the distributor, that is, is locatedwhere the "ice liquid is already rotating at substantially full speed,whereupon it is fed into the separation chamber proper. Alternatively, aliquid-separating, porous body may be provided which separates a part ofone of the liquids so that it never flows into the separation chamber,while the rest of the liquid mixture passes through the body and flowsinto the separation chamber. It is also possible to use a combination ofa coalescing and liquid-separating body, so that the liquid mixturefirst passes through the coalescing body and thereafter through theliquid-separating body, or conversely. In the former case, a space ispreferably provided between both bodies, from which space the liquidwhich does not flow through the second porous body, considered in thedirection of flow, is conveyed to a corresponding outlet.

The invention is also applicable to a separator with a set of discswhich, as well as the distributor, is provided with distribution holes.In that case, coalescing, porous bodies may be inserted in thedistribution holes, these bodies being preferably in the form of tubeswhich extend axially through the holes; or a coalescing, porous body maybe arranged axially, so that it obturates the distribution holes in thedistributor. Alternatively, it is also possible to arrange a liquidseparating, porous body so that it obturates the distribution holes orto arrange a combination of a coalescing and a liquid-separating body inthe same manner.

Finally, in order to eliminate the last traces of heavy liquid from aseparated, cleaned light-weight liquid, or conversely, it is possible toarrange, near the outlet for one of the liquids from the rotor orseparation chamber, a substantially tubular or ring-shapedliquid'separating, orous body which is coaxial with the axis of rotationof the separator.

The invention is described more in detail below, referonce being made tothe attached drawings in which:

FIG. 1 is a vertical sectional view of a centrifugal separator embodyingthe invention in one form, and

FIGS. 2 through 9 are vertical sectional views of parts of centrifugalseparators embodying other forms of the invention.

In FIG. 1, reference numeral 1 designates the rotor of the separator and2 the vertical spindle carrying the rotor. Reference numeral 3designates the hood of the rotor and 4 the lock ring which fastens thehood to the rotor. The liquid mixture to be separated is fed in througha stationary pipe 5. The rotor is provided with a distributor 6 withwings 7 and a set of discs 8 with a top disc 9. The distributor and thedisc set are provided with vertically aligned distribution holes 10.Heavy liquid is discharged through an overflow 11 and light-weightliquid through an overflow 12.

The feed pipe 5 is provided with a coalescing plug 13. The latter may bemade of felted glass fibers in which the pores cons'itute, for example,to of the volume of the plug. Instead of a plug, it is possible to use atubular body with a closed bottom end, the walls of the tube beingpreferably corrugated in order to constitute a large through-flow areafor the liquid mixture passing through it.

In FIG. 2, a coalescing body 14 of the same kind as that shown in FIG. 1is located in the distributor 6 instead of the pipe 5. The body 14therefore differs from the body 13 only by its larger diameter.

We have shown in FIG. 3 a number of coalescing bodies 15 of the samematerial as the body 13 according to FIG. 1. The bodies 15 are insertedin the channels formed between the wings 7 and of which there may beeight in number, which lead from the center of the distributor 6 to itsperiphery, there being a body in each channel. The bodies 15 cover thethrough-flow area in each channel so that the whole liquid mixturesupplied to the separator must pass through the bodies.

In FIG. 4, which shows the right-hand part of a partial section througha rotor, a tubular or ring-shaped porous body 16 is provided. This bodymay be of a coalescing or liquid-separating type or a combination ofboth types. If the body is of the liquid-separating type, it may beconstituted by a fine-mesh wire cloth (width of mesh, 5 to 70a, forinstance), the wires of which are preferably fixed in relation to eachother by sintering. In this embodiment, the distributor 6 is notprovided with any distribution holes and therefore the liquid mixture iscompelled to stream radially inwards from the space outside the body 16.The liquid separating by the body 16, if the latter is of theliquid-separating type, is supposed to be the heavier one and thereforemoves radially outwards.

In FIG. 5, we have shown the right-hand part of a partial sectionthrough a rotor with tubes 17 of coalescing material inserted in thedistribution holes of the disc set 8.

In FIG. 6, which shows the right-hand part of a partial section througha rotor, coalescing and liquid-separating bodies 18 and 20 are arrangedat the underside of the distributor 6, these bodies having the shape ofconical discs. The liquid mixture passes first through the coalescingbody 18 and thereafter enters an interspace 19 between said body and theliquid-separating body 20. The liquid which does not pass through thebody 20, and which in this case is supposed to be the heavy liquidphase, moves outwards to the outer edge of the body 20 while the liquidwhich has passed through the body 20 moves upwards in the disc setthrough the distribution holes 10.

As illustrated in FIG. 7, which shows the right-hand part of a partialsection through a rotor, a plate 21 of coalescing material is arrangedat the underside of each distribution hole in the distributor 6. A slot22 is arranged between each plate 21 and the distribution hole, and aplate 23 of liquid-separating material is inserted in each distributionhole. This embodiment operates in principle in the same way as theembodiment according to FIG. 6.

The liquid-separating body shown in FIG. 8 is a largesized tube 24inserted close within the inner edges of the disc set 8. The tube 24separates small droplets of heavy liquid which move out into theseparation chamber through the disc set 8 while the light-weight liquidpasses through the tube 24 and reaches its outlet 12. Conversely, it ispossible to arrange a similar tube of a still larger diameter at theouter edge of the top disc 9, which tube prevents droplets oflight-weight liquid from being entrained by the heavy liquid passing tothe outlet 11.

A modification of the embodiment according to FIG. 8 is shown in FIG. 9.In this modification, the liquid-separating body has the shape of a ring25 inserted in the neck of the top disc 9, that is, just ahead theoverflow 12 for the light-weight liquid. The ring 25 operates in thesame way as the tube 24 in the embodiment according to FIG. 8.

We claim:

1-. In a centrifugal separator for continuously separating two liquidsfrom each other, the combination of a rotor having an inlet for saidliquids and having a sepa rating chamber including an outer peripheralportion and a main separating space, the rotor also having twopermanently open outlets for the respective separated liquids and spacedradially inward from said outer portion of the separating chamber, saidrotor defining completely open feed passages from said inlet to saidouter portion, said open feed passages having a radially outer portionopening into said outer portion of the separating chamber, the

rotor also defining first and second flow paths leading from at leastone of said outer portions of the feed passages and separating chamberto the respective outlets, said first flow path including said mainspace of the separating chamber, and a porous body inserted in one ofsaid how paths in position to permit free flow of solids from said inletto said outer portion of the separating chamber.

2. The combination according to claim 1, in which said porous body is ofthe type operable to coalesce droplets of one of said liquids passingtherethrough.

3. The combination according to claim 1, in which said porous body is ofthe type operable to block the passage of one of said liquidstherethrough.

4. The combination according to claim 1, in which the rotor includes adistributor partly defining said open fee-d passage, said porous bodybeing a tubular member coaxial with the rotor axis and surrounding theperiphery of the distributor.

5. The combination according to claim 1, in which the rotor includes adistributor partly defining said open feed passage, and a set of discsin said main space of the chamber, said distributor and disc set havingdistribution holes in which said porous body is located.

6. The combination according to claim 1, in which the rotor includes adistributor partly defining said open feed passage, and a set of discsin said main space of the chamber, said distributor and disc set havingdistribution holes in which said porous body is located, said body beinga tube extending through said holes substantially parallel to the rotoraxis and being of the type operable to coalesce droplets of one of saidliquids passing from said holes to said chamber.

7. The combination according to claim 1, in which the rotor includes adistributor partly defining said open feed passage, and a set of discsin said main space of the chamber, said distributor and disc set havingdistribution holes, said porous body covering a distribution hole in thedistributor.

8. The combination according to claim 1, in which said porous body isinserted in said first flow path. a

9. The combination according to claim 1, in which said first flow pathincludes an annular space located radially inwardly from said main spaceof the separating chamber, said porous body being a tubular memberinserted in said annular space.

19. The combination according to claim 1, in which said porous body isof the type operable to coalesce droplets of one of said liquids passingtherethrough, the combination comprising also a second porous body ofthe type operable to block the passage of one of said liquidstherethrough, said second body being inserted in said one flow pathdownstream from the first porous body and defining therewith a passageleading to said peripheral portion of the separating chamber.

References Cited UNITED STATES PATENTS 1,614,357 l/1927 Gamper 233-22,594,445 4/1952 Keith 233-2 FOREIGN PATENTS 1,362,722 4/1964 France.

262,902 12/ 1926 Great Britain. 335,466 9/1930 Great Britain. 915,879 l/1963 Great Britain.

HENRY T. KLINKSIEK, Primary Examiner.

